MECH3035 Design Project spring 2020
Objective: To apply the methods of analysis of mechanics, machine design and strength of materials to a proposed case study.
Case study:
Analysis of the mechanical elements of a mechanical ventilator using a bag valve mask (BVM).
What is required: For the given step file determine the dimensions of the links and the size of the bolts and pivots for a SF of 2 and an infinite fatigue life. In your report you need to show all work and calculations. I am looking for a minimum size of the elements so that the safety factor is between 2 and 10 if possible. I have arbitrarily set the dimension for the elements at around 10 mm for the thickness and 6 mm for the screws and pivots. The positions of the elements should remain set as given in the step file, you are to determine the correct sizes for thickness (this will be dependent on the pitch of the thread) and width of the links. For assembly the components that are screwed together will need at least three threads, which will limit your minimum thickness. Also, if using shoulder bolts then there is a minimum length of thread on commercial shoulder bolts which could be reduced if needed.
Material is your choice just be able to justify. Assume the rocker arms will have a load of about 35 N max. Assume the motor should be able to deliver enough torque to drive the mechanism.
I have provided videos for the source of the idea and put it into a cad file. I changed the notched link to a curved beam.
These are examples of the mechanism we are supposed to analyse and report on. We are looking at the linkages attached to the motor that's moving the entire system.
https://www.youtube.com/watch?v=evWKC7D35AE
https://www.youtube.com/watch?v=6Tm7sM6j3g8
https://www.youtube.com/watch?v=Qs5tV5t8H_Q
https://www.youtube.com/watch?v=SOVQIx0On30
If you could write this in a case study format, that would be great! And example of a case study format is attached: